Buffer for electric switches



Jan. 28, 1930. C, F, SCHWENNKER 1,745,122

'BUFFER FOR ELECTRIC SWITCHES Original Filed Jan. 5, 1924 Inventor` ChclrLes F, Schwennker,

HLS Attornegy.

Patented dan. 28, 1931) PATENT OFFICE CHARLES F. SCHWENNKER, GF SUHENECTADY,"

ELECTRIC COMPANY, A

YQRIL, ASSIGNOR 1Y0 GENERAL CORPORATIQN OE NEW YORK BUFFER FOR ELECTRIC SllLCI-IESl Original application filed January 5, 1924, Serial No. 684,669. Patent No. 1,569,683, dated January 12, 1526.

Divided and this application filed November 5, 1925.

My invention relates to electric switches and more particularly to a butter arrangement adapted for checking` movement of the moving` parts of the switch. My invention also relates to the structure oit an improved buil'er which is simple in construction, easily adjusted and effective to check an operating,` member in each of two directions 'ot 1novenient.

The present application is a division of my copendingapplication, Serial No. 664,669, filed January 5, 19211 now Patent No. 1,569,- 683, issued January 12, 1926 for an electric switch.

My invention will be better understood Ytrom the following description taken in cono nection with the accompa[lying` drawing, and its scope will be pointed out in the appended claims.

In the drawing Fig. 1 is a vertical sectional view of a iluid break switch involving my invention and Fig. 2 is a detail view.

ln the drawing l have shown by way ot eX- amplc a iluid break switch in which the opu crzfi'ing mechanism is located within the enclosing' structure of the switch.- This structure congiprises the tank 1 and the top casing; 2 secured together by holte 3. rllhrough the cover l ot the casinov extend the two insulator bushings 5, to the inner ends of which are secured the stationary contacts 6. The bridging' contact member 7 cooperates with the contacts 6 to open and close the circuit connected therewith. The operating rod 8 terminates at its upper end in a terrule 9 through which extends the pin 10. The switch actuating mechanism, a portion only ot which illustrated, includes the bifurcated lever 12 through the ends of the two arms olf which pass the pin 10, and the link 13 pivoted to the lever 12 and to a stationary point 141 by means of which the operating rod is caused to move in a straight line. Each arm of the lever 12 has an outwardly extending iiangc 15 having` an elongated opening `for receivingone of the screw-threaded rods 16. Heads 17 on these rods limit the downward movement of the lever. Directly over the operating rod 8 is the hollow bracket 18 shown secured to the cover 4 by bolts 19. The

Serial No. 67,137.

danged button 2O rests in the lower portion of the bracket- 18 and the bar 21 extends through transverse slots formed in the upper portion thereof. Between the button 20 and the bar 21 are shown a series Ot felt disks. 22, which form the cushioning means. The rods 16 are threaded through the bar and abut the under side of the cover. Then the switch is tripped open the downward movement of the operating parts is checked by the felt disks 22, when the lever 12 reaches the heads 17 of the rods 16. Similarly when the switch is closed, the upward movement of the parts is checked; by the same disks when the pin 1() engages button 20. By turning the rods 16 the felt disks may be lgiven the necessary initial compression to. give them the desired degree of hardness.

It will be noted that with the construction I have disclosed, the same set of disks. is used to check or cushion both the opening and the closingA` movement of the switch mechanism and also that adjustment of the initial compression ofthe disks does not atleet the length or". stroke ot the switch, nor does it affect either of the limiting; positions of the movable contact member. The latter is of particular importance since as a result damage to the Contact brushes due to overtravel of the parts in the closing` movement may be avoided.

While I have described only one embodiment of my invention, I do not wish to be limited to the particular' form shown and described, as it will be apparent that many modifications therein may be made without departing from the scope of my invention as set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent of thcUnited States is:

`1. An electric switch having a movable contact member and a buiier for checking movement thereof comprising a cushioning' member, a support therefor, means for cornpressing the cushioning` member by the movable member when the latter reaches predetermined positions in its movement in opposite directions and means whereby the initial compression of the cushioning member may be varied without changing said predetermined positions.

2. An electric switch comprising a movable contact member having limiting positions of movement, a butl'er therefor comprising a cushioning member', means whereby the cushioning member is stressed by both the forward and the return movement of the contact member, and means for varying the initial stress of said cushioning member without aecting said limiting positions.

3. An electric switch comprising a Contact operating member, and a butler comprising a support, a fixed cushioning member carried thereby, means for putting said member under initial compression and means cooperating therewith whereby the cushioning member is further compressed by the opening movement and by the closing movement of the operating member.

4. An electric switch comprising a movable contact. an operating member therefor, and a butler having a cushioning member and a lost motion connection with the operating member, means for giving the cushioning member a permanent initial stress and means whereby the cushioning member is stressed an additional amount by the operating member when the latter reaches either end of its n'iovemcnt.

5. An electric switch comprising a switch operating member, a butler comprising a fixed cushioning member, adjustable means engaging opposite sides of the cushioning member for giving the member a permanent initial compression, and means engaging said adjustable means whereby movement of the operating member beyond a predetermined point causes further compression of the cushioning member.

6. An electric switch comprising a contact operating member, means for limiting the closing and the opening movement thereof comprising a cushioning member, and means for varying the initial compression of the cushioning member without affecting the tinal limits of movement of the operating member.

7. An electric switch comprising a contact operating rod, means for moving the rod longitudinally to close and open the switch, and a butter for limiting the movement of the rod, said buffer comprising a cushioning member, a support therefor, a pair of members between which the cushioning member is clamped, one ot' said members heilig adapted. to be engaged by the operating rod when the switch reaches closed circuit position, and means connected with the other of said members adapted to be engaged by the operating rod when the switchreaches open circuit position.

8. An electric switch having a liXed contact, a cooperating contact arranged to have a definite opening and closing movement relative thereto, and a buffer for the movable contact comprising a single cushioning member constructed and arranged to cushion the movable contact at the end of both its opening movement and its closing movement.

In witness whereof, I have hereunto set my hand this 4th day of November', 1925.

CHARLES F. SCHVVENNKER. 

